I'm 13, I used to think to be told that you can only have certain horse for certain disciplines. HA! I laugh at that now as that was 4 years ago. I bought my first horse as an 8 year old(now 12) and she was trained under saddle and had some experience. I completed her training. And now she does ALL western disciplines(halter-to cutting you name it) and has done some level 1, 2 dressage. I have met many girls, my age, who have wanted horses only for social purposes and to 'make them look good'. I have NEVER had that outlook. I want horses for a career. It sounds as though your daughter is taking control. I agree COMPLETELY that she needs to take responsibility. I groom, ride, and take FULL care of my baby, Charm. And my dad's horse, Boston, as he is out of town for several months. I would suggest not getting her another horse at all, if she wants another horse make HER train it like I did mine. There are good all around horses out there you know, take mine for example, she never refuses anything. It would bring your daughter a lot closer to horses. Good luck!